1. Field of the Invention
The present invention relates to an endoscope apparatus which performs observation and therapeutic procedure within a body cavity and, more particularly, to an endoscope apparatus which is provided with cleaning means for performing feed liquid, feed gas, suction or the like with respect to a view window portion at a forward-end part or a distal part of an insertion section of the endoscope apparatus, to maintain a superior field of view.
2. Description of Related Art
At present, various kinds of endoscopes for performing observation and therapeutics procedure within a body cavity or the like have been used in various kinds of fields such as a medical treatment or the like. There are many cases where such endoscopes are used under environments in which inserting sections or distal parts thereof are apt to become dirty. A view window which is provided in the distal part of the endoscope must particularly be kept always clean, in order to produce a superior field of view.
In view of the above, a prior art endoscope is provided, for example, with, as cleaning means, means in which a flow passage for passing fluid such as water or the like for cleaning is provided, and a nozzle which is in communication with the flow passage is provided at a distal part, for blowing the cleaning fluid against a viewing window at the distal part of an inserting section, feed liquid of the cleaning fluid is performed toward the viewing window to wash away dirt and dulling or hazing, or feed gas is performed to the observation window to remove remaining water drops. Further, there is also a case where, as the cleaning means, the endoscope is provided with means, in addition to the feed water means to the observation window, in which a suction passage is provided to suck the dirt and the water drops remaining in the vicinity of the observation window.
As the endoscope apparatus which is provided with the cleaning means for performing feed liquid, feed gas, suction or the like with respect to the observation window at the distal part of the insertion section, an arrangement in which the passage or a nozzle is provided at the insertion section of an endoscope body is general. However, as an arrangement in which a sheath is detachably covered on the inserting section of the endoscope, an arrangement or the like has been proposed in which the passage or the nozzle is provided in the sheath.
With the arrangement of the endoscope apparatus which is provided with the prior art cleaning means as described above, the cleaning passage or nozzle is provided in the sheath which covers the endoscope body or the endoscope. For this reason, there have been cases where the apparatus arrangement complicates assembly of a line tube and a nozzle; formation of the nozzle which is provided at the distal part has been particularly difficult, and formation of the cleaning passage and the nozzle has been difficult so that much labors have been required. Accordingly, the following problems have been generated. That is, the arrangement of the cleaning means becomes expensive, with increased time consumption during operation upon assembling.
Moreover, there are the following problems. That is, for the arrangement in which the cleaning passage and nozzle are provided in the endoscope body or in the sheath as is in the prior art, since an elongated line and a nozzle whose shape or form is narrow and is complicated are assembled with the endoscope body or the sheath, it is difficult to wash or clean a portion of the line or the nozzle when washing or cleaning is performed after use of the endoscope during inspection or examination so that much time is consumed for cleaning and disinfection or sterilization.
Furthermore, in recent years, as an arrangement of a disposable or throwaway type in which a treatment tool or the like is cancelled without being washed or cleaned after use, a medical harness has been put to practical use in which a new sterilized arrangement is used during every use, and time spent in cleaning or the like is reduced so that therapeutics procedure and examination can efficiently be performed while easily keeping a clean state or condition.
For example, in the situation where an endoscope in which an inserting section which is used during insertion into a peritoneal cavity or the like in a patient to perform observation is difficult to adapt to a disposable type, since a complicated arrangement including a hard mirror as in the prior art is expensive, it is impossible to apply the endoscope to the disposable type as it is. Particularly, in case where the aforementioned cleaning means is added, the arrangement or structure is further complicated. In order to arrange the hard endoscope provided with the cleaning means, at a low cost, so as to be disposable, it is necessary that the number of parts is reduced as much as possible, while improving ease of assembly.